In an examination using an MRI apparatus, a cross section which is anatomically determined is usually imaged for every part to be examined. This cross section is called an examination section. In the examination, this examination section is set as an imaging slice for each subject. However, since it takes skill to set the imaging slice, variations in setting may occur between operators. In particular, in a joint region with a complicated anatomical structure or the like, the setting is difficult. For this reason, a part to be examined (for example, a ligament or cartilage) may not be included in the set imaging slice. In addition, it may take a lot of time to set the imaging slice according to the skill of the operator.
In addition, for example, the same part of the same subject is continuously imaged in postoperative follow-up examinations. In such a case, it is difficult to set an imaging slice at the same position of the subject each time. In order to solve this, a function of setting an imaging slice at a desired position automatically has been proposed (for example, refer to NPL 1). NPL 1 discloses a technique of setting an imaging slice of an image for examination automatically using 3D volume data acquired in advance.
The imaging slice setting procedure herein is shown in FIG. 22. As shown in this drawing, scanogram imaging for acquiring a two-dimensional (2D) scanogram image for positioning is performed (step S1301), and then 3D volume imaging for automatic positioning which is for acquiring 3D volume data is performed in order to calculate a recommended imaging slice for main imaging (step S1302). Then, a recommended position for main imaging (recommended imaging slice) is calculated from an image acquired by this 3D volume imaging (step S1303), the recommended position for main imaging (recommended imaging slice) is displayed (step S1304), and then the main imaging is performed (step S1305).
According to the technique disclosed in NPL 1, it is possible to set the imaging slice plane without depending on the skill of the operator. However, not only the normal 2D scanogram imaging but also 3D volume imaging is needed before main imaging. For this 3D volume imaging, it takes about 2 minutes including the time to reconstruct an image from the 3D volume. Accordingly, the examination time is greatly increased.
Moreover, in the examination using an MRI apparatus, a diagnosis on the same examination section is made by comparison between images with different contrast in many cases. Therefore, in one examination, a plurality of images with different contrast are captured for the same examination section. For example, in the case of a medical checkup of the brain, a T1 weighted image, a T2 weighted image, FLAIR (or a proton density image), and a T2*weighted image are acquired using as the examination section a plane along the OM (Orbit-Meatus) line or the AC-PC (Anterior Comisure-Posterior-Comisure) line (refer to NPL 2).